1. Field of the Invention
The present invention relates to an improved method and device for determining the presence of certain components in human urine. In particular, the present invention is directed to a urine self-test device, comprised of biodegradable materials, which can be placed directly into the toilet after urination for detection of predetermined substances which may be found within the urine. While the invention can be configured to detect any substance ascertainable within urine, the invention is directed particularly to urine testing for pregnancy.
2. Description of the Related Art
Many medical diagnostic tests require the detection of specific components which are found in urine specimens. Most medical tests for the presence of components in the urine are conducted in a laboratory. However, there are many benefits to self-administered medical tests including decreased costs, saving of time and increased privacy. The most common example is that of the home pregnancy test which generally utilizes a human chorionic gonadotropin (hCG) indicator which changes color if hCG is found in the urine which is suggestive of pregnancy.
Despite the advantages of self-testing, the handling of urine and urine-ladened test devices is objectionable. Further, the disposal of non-biodegradable testing devices can be objectionable, particularly when privacy is desired and the device can not be conveniently or discretely disposed.
At present, devices are available for self-administered urine testing for: pregnancy, pathological growths such as hydatiform mole or choriocarcinoma which may cause hCG secretion and for determining blood in the urine. There is an increase in self-administered medical testing specific to urine due to the ease of testing, decreased medical cost and generally decreased time for return of test results. While there has been an overall increase in self testing, pregnancy testing in particular has greatly improved over the past few decades. Early pregnancy tests required a visit to a physician who would draw blood and conduct fairly elaborate chemical tests, often requiring the use of a host animal which had to be killed. Further, it could take several days for the return of the test results. Laboratory methods eventually developed which avoided blood sampling, and the death of animals, by conforming the test process to urine samples in which can be detected hCG during pregnancy. A home sampling test was developed as disclosed in U.S. Pat. No. 4,315,908, although the sample had to be sent to a laboratory for analysis by radioimmunoassay. Finally, a test was developed which allowed a home pregnancy test to be totally self-administered with results available in just a few minutes.
Several companies manufacture home pregnancy tests which are available on the market at nominal prices. All of the home pregnancy tests currently available utilize a specimen collector or indicator which is held in the stream of urine during normal urination or dipped into a container of collected urine. If the woman is pregnant, it is likely that hCG will be secreted within the urine. A predetermined indicator such as a monoclonal antibody specific to the beta subunit of hCG is provided by the testing device and will change color, or provide some other visible indication, if hCG is present and detected. It is well known within the art how to provide reagents which change color, or provide some visible reaction, when subjected to urine containing hCG, even in dilute amounts which may be present in a toilet bowl after urination. Most of the available testing devices also provide a control indicator to show that the test performed as indicated. However, the indicator portion of the test device is often small with the color differentials between a positive result and a negative result being difficult to distinguish. Some of the test devices provide a + or xe2x88x92 symbol for positive or negative results, with the symbols being so small as to require close and careful inspection of the urine laden device.
The known home pregnancy tests have several other problems. Women are generally dissatisfied with the present devices due to the necessity of holding the test indicator directly in the stream of urine, or collecting urine in a specimen container so that the indicator may be placed therein. Either of these methods often produce the undesirable result of contacting the urine stream with a hand or clothing. Further, during the requisite period of waiting for the test results, the device must either be held in the hand or placed on a level surface which increases the likelihood of dripping or spilling urine. After the test is completed, the indicator device must be disposed into the trash, often resulting in the further dripping or spilling of urine. While some of the testing devices function properly in diluted urine, they are not suitable for disposal into the sewer system for physical reasons of structural stability, size and inert or non-biodegradable content. Further, the small indicator portions provided on the known test devices can not be seen without close inspection.
Pregnancy test results can produce a wide range of emotion and the experience is not enhanced by the perceived nastiness of the testing process. Additionally, if the testing process is a private matter, the secrecy of the process may be jeopardized if the test indicator is not properly disposed. It is desirable to have a test indicator which does not have to be handled after it is subjected to contact with urine and which does not have to be disposed of in the trash.
It is an object and purpose of this invention to provide an urine test device which does not have to be handled after being subjected to urine.
It is also an object and purpose of this invention to provide a visibly reactive response to the persence of hCG in dilute urine, with the reactive response readily visible to the user.
It is a further object and purpose of this invention to allow the user of the urine test device to read the results from a distance, particularly while it is in the toilet bowl containing dilute urine.
Yet another object and purpose of this invention is to provide a biodegradable alternative to the known urine test devices thereby allowing the urine test device to be safely flushed into a sewage system or septic system.
The home testing device of the present invention provides a method and apparatus that overcomes the stated deficiencies of the prior art as it allows the user to place the device directly into the toilet after urination where the test results can easily be viewed and as it is flushable into the sewer system by the nature of being compact and biodegradable. The device may be placed into the toilet after urination by dropping or by suspending it on a tether. The device will float in the toilet and will provide either a positive or false indication after a predetermined duration of exposure to the dilute urine.
The device can be constructed with indicator viewing areas on both planar surfaces so that the device can be dropped into the toilet in any position. Alternatively, if only one indicator viewing port is provided a tether can be affixed to the device. so that the view port remains oriented upward when the device is lowered into the toilet. The indicator viewing areas will be of sufficient size so that the test results can be easily viewed at a reasonable distance.
All of the device which has come into contact with urine will be biodegradable and may be flushed into a sewage system or septic system leaving only a sanitary wrapper to be disposed. Alternatively, in a situation where solids are not desired to be introduced to the sewage system, the optional tether may be used to suspend the device in the toilet during the test and then to retrieve the device for disposal without necessitating direct contact with the contaminated portion of the device.
Variables inherent in most medical testing, as with urine specific pregnancy testing, are well known within the art. It is also known by those skilled in the art of home pregnancy testing the parameters necessary to obtain accurate test results of positive gonadotropin presence indicative of pregnancy. Dilute volumes of urine may be accurately tested using indicator devices currently available on the market, such as the pregnancy indicator device marketed under the trade name Early Pregnancy Test (E.P.T.) or the QuickVue device manufactured by Quidel Corporation. Further, testing discloses that pregnancy indicator devices readily available on the market, such as those indicated above, perform accurately when subjected to common household cleaners and disinfectants used in toilet bowls.
Inherent in home testing devices is the statistical likelihood of a false result due to variables not normally present in clinical testing environments. Manufacturers can not develop home testing devices which overcome any and all variables and typically solve this problem by providing instructions and directions with the testing device to eliminate or control variables and to warn the user of possible false results when the testing is not conducted in a controlled environment. Most existing devices direct users to test urine after sleeping because urine volume will be great as will the urine concentration. For the instant device, it is necessary to provide instruction and direction to the ultimate user such as is currently provided with the earlier types of home pregnancy devices.
While experimentation shows that devices currently available on the market will accurately perform in most environments normally found in residential toilets, cautionary information will necessarily be provided to the consumer. Experiments were conducted using pregnancy indicator devices commonly used and well known within the industry. Variables were utilized to closely simulate conditions common to residential toilets. Toilets having varying water levels between six (6) and eight (8) liters were tested using between fifty (50 mL) and one hundred milliliters (100 mL) of urine. Further, experiments were conducted where common toilet bowl cleaners were incorporated into the varying levels of water within a toilet bowl. All experiments using the subject invention, wherein the test indicator strip was comprised of hCG detection components readily found in over the counter pregnancy testing devices, provided highly accurate and consistent readings. Between fifty (50 mL) and one hundred (100 mL) milliliters of urine from a pregnant female, less than the average urination volume, will provide a positive reaction for the presence of hCG when diluted in approximately six to eight liters of water, the amount found in most residential toilets, using known visual indicators similar to those currently available.
It is necessary to ensure direct contact of urine, even in dilute amounts, with the indicator device. Therefore, in one configuration of the invention, a wicking device is secured to one end of a housing, which encompasses the indicator strip, which facilitates the movement of dilute urine into the housing for direct contact with the indicator strip. Another configuration of the invention uses a planar housing which lies flat on, or near, the surface of the liquid within the toilet bowl, thereby allowing the indicator device to directly contact the dilute urine.
Yet another configuration of the invention provides the paper-like indicator device encircled about a cylindrical wick. The wick absorbs the dilute urine through the open ends and disposes the dilute urine directly onto the indicator device. The entire surface of the indicator will be provided with reagent which changes color in the presence of predetermined substances within urine, such as hCG. The device will have a clear protective covering over the indicator to maintain its integrity during the testing process.
In any of the configurations described, each component will be constructed of biodegradable materials which do not immediately decompose or alter configuration when subjected to the test liquid for a period of time sufficient to allow the reagents provided on the indicator to react to components within the urine, if any. The invention, in any of the described configurations, will be provided with a negative control on the indicator device which will visibly change color after the invention has been subjected to the dilute urine for a period of time sufficient to produce a positive reaction in the presence of the predetermined component within urine, thereby signaling the user that the device worked correctly, but the sought analyte was simply not present. In the case of pregnancy testing, when the negative control changes color, but the indicator device does not, it will signal the user that no hCG is present and that pregnancy is not likely indicated.
As is known within the art, visible reaction to the presence of hCG may be accomplished by using an indicator provided with an antibody and enzyme reactive to a component of hCG. Even very dilute amounts of urine from a pregnant woman contains sufficient amounts of hCG for components found within hCG to attach to the antibody provided and to initiate a color change within the antibody indicative of molecular binding between the antibody and components of the hCG, thereby indicating the presence of hCG within the urine.